This invention relates to an improved heat exchanger having primary and secondary fluid passages with a nickel rich barrier interposed therebetween. These panels find particular application in heat exchange systems which utilize primary and secondary fluids, whether gas or liquid, which should not be intermixed as a result of corrosion effects.
In many heat exchange systems utilizing two or more heat transfer fluids intermixing of the fluids is highly undesirable and/or dangerous. For example, an ethylene glycol base anti-freeze solution may be used in the primary loop of a solar heat exchanger to avoid freezing of the solar absorber panels during cold weather. In such a system the secondary loop may contain water which may be used for drinking or in household appliances. Ethylene glycol is highly toxic and it can readily be seen that intermixing of the ethylene glycol with the water would be quite dangerous.
Another example of undesirable mixtures of primary and secondary heat exchange fluids would be the use of an organic heat transfer fluid in the primary loop which may contaminate water in the secondary loop. Other examples would include cases where the two fluids are chemically incompatible or where a safety hazard may result.